The invention relates to an electronic locking system for a vehicle.
To accommodate increased security requirements, electronic locking systems are used, which operate, for example, by means of electromagnetic waves. In particular in motor vehicles, such locking systems are used for door locking, access authorization and/or ignition locking, steering wheel locking, and immobilizers or the like for driving authorization.
Such a locking system is disclosed, for example, in German patent document DE 43 40 260 A1, in which a control device that has at least two states is provided for unlocking and/or locking the car doors, the ignition lock or the like, and a second device is provided in the form of an electronic key. The two devices have means for transmitting and/or receiving signals, whereby at least one signal can be means for transmitting and/or receiving signals, whereby at least one signal can be transmitted between the key and the control device as a coded operating signal for authenticating the key, to change the state of the control device after the transmitted operating signal has been evaluated, and thus when the key is authorized.
Such locking systems which are operated manually have also been further developed as so-called “keyless” functions, for which it is no longer necessary for the user to activate the electronic key manually. Rather, it is sufficient for the user to carry the key on his person. The operating signal is then transmitted automatically for access authorization between the two devices if the user is located in an active region in the vicinity of the motor vehicle, and (for example in “keyless entry” systems) activates the door handle on the car door there. Likewise, these locking systems may have a “keyless go” function, in which the operating signal for driving authorization is transmitted automatically between the two devices if the user is located within the motor vehicle and, for example, activates a start/stop pushbutton key on the dashboard.
In order to provide such keyless functions, the key is continuously in the standby state, and thus continuously consumes energy, even in the case of a new key which has not been used at all. When a key is in storage, for example before the motor vehicle is delivered, or also when the key is a spare key, this can prematurely exhaust the battery located in the key. In an extreme case, the key may even no longer be operable when it is delivered to the user.
European patent document EP 1 127 757 A2 describes a locking system, in particular for automatic access authorization, a keyless entry/go function, manually actuated access authorization and/or driving authorization for a motor vehicle. A control device, which has at least two states, is provided for unlocking and/or locking car doors, the ignition lock, the steering wheel locking means, or for enabling and/or disabling the immobilizer, the engine control unit or the like, in conjunction with a second device, such as an electronic key, an ID transmitter, chip card or the like. Means are provided for transmitting and/or receiving signals, between the control device and the second device, including in particular a coded operating signal for authenticating the second device. After positive evaluation of the operating signal, a change in the state of the first device can be brought about when the second device is authorized.
In the locking system disclosed in German patent document DE 43 40 260 A1, an electronic ignition lock for the manual driving authorization is arranged in the motor vehicle. The ignition lock has a receptacle into which the second device is inserted by the user for manual authentication.
One object of the invention is to provide locking system with a “keyless” function, in which the consumption of energy before the key is delivered is reduced.
This and other objects and advantages are achieved by the locking system according to the invention, in which, before its initial activation the second device (a key) is in a sleep state such that automatic operation is not possible, and energy consumption is reduced. During the first manual authentication (that is, during the initial authentication), the second device is changed over from the sleep state into a standby state in which automatic operation is at least partially possible.
According to a feature of the invention, the ignition lock is also in the initial authentication, for changing over the second device from the sleep state into the standby state. For this purpose, the initial authentication in the ignition lock is carried out after the key which is used as the second device has been plugged into the receptacle. Advantageously, this can be carried out by the user himself, so that the energy saving continues until the key is actually used. Furthermore, the initial activation of the key can also be carried out without additional devices, and consequently without additional costs.
In one embodiment of the invention, the second device is completely switched-off in the sleep state. As a result, the second device consumes essentially no energy before the initial activation. The second device is expediently in the sleep state while it is being manufactured and in particular while it is being delivered to the user. As a result, the second device itself is still in the “new” condition, even when it has been stored a long time before being delivered.
The invention makes it possible to save energy for the second device until it is used, including, for example, when the device is still in storage. As a result, the service life of the battery in the second device is prolonged. If the second device is a spare key, it is possible to advantageously prevent a situation in which the battery of the key becomes prematurely exhausted and the key is not ready for use in an emergency situation.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.